Supersensitization of photographic emulsions using triazines



United StatesPatent SUPERSENSITIZATION F PHOTOGRAPHIC EMULSIONS USING TRIAZINES Burt H. Carroll, Jean E. Jones, and John Spence, Rochester, N.Y., assignors to Eastman Kodak Company, Rochester, N.Y., a corporation of New Jersey Filed Oct. 12, 1955, Ser. No. 540,054

20 Claims. (Cl. 96-100) This invention relates to photographic silver halide emulsions useful in color photography and photographic silver halide emulsions containing dicarbocyanine dyes, and as supersensitizers therefor, triazine compounds.

It is known in the art of making photographic emulsions that certain dyes of the cyanine class alter the sensitivity of photographic emulsions of the gelatinosilver-halide kind, when the dyes are incorporated in the emulsions. It is also known that the sensitization produced by a given dye varies somewhat with the type of emulsion in which the dye is incorporated. Furthermore, the sensitization of a given emulsion by a given dye may be altered by varying the conditions in the emulsion. For example, the sensitization may be increased by increasing the silver ion concentration or decreasing the hydrogen ion concentration (i.e., increasing the alkalinity) or both. Thus, sensitization can .be increased by bathing plates, coated with a spectrally sensitized emulsion, in water or in aqueous solutions of ammonia. Such a process of altering the sensitivity of a sensitized emulsion by increasing the silver ion concentration and/or by decreasing the hydrogen ion concentration is commonly called hypersensitization. Hypersensitized emulsions have generally poor keeping qualities.

We have now found another means of altering the sensitivity in emulsions containing dicarbocyanine dyes. Since the conditions in the emulsion, i.e., the hydrogen ion and/or the silver ion concentration undergo little or no change in our method, we shall designate our method as a kind of supersensitization.

It is, therefore, an object of our invention to provide photographic emulsions containing dicarbocyanine dyes and, as supersensitizers therefor, triazine compounds. Another object is to provide a process for preparing these supersensitized emulsions. Still another object is to provide photographic emulsions containing triazine compounds which are especially useful in color photography. Other objects will become apparent from a consideration of the following description and ex amples.

The tdicarbocyanine dyes which are useful in practicing our invention can advantageously be represented by the following general formula:

wherein R and R each represents an alkyl group (such as methyl, ethyl, B-hydroxyethyl, carboxymethyl, B-carboxyethyl, carbomethoxymethyl, carbethoxymethyl, etc., 21 represents a positive integer of from 1 to 2, X represents an acid radical, such as chloride, iodide, bromide, perchlorate, p-toluenesulfonate, benzenesulfonate, ethylsulfate, methylsulfate, etc., Z represents the non-metallic atoms necessary to complete a heterocyclic nucleus containing from 5 to 6 atoms in the heterocyclic ring, e.g., a heterocyclic nucleus of the benzothiazole series (e.g., benzothiazole, 4-chlorobenzothiazole, S-chlorobenzothiazole, 6-chlorobenzothiazole, 7-chlorobenzothiazole, 4-

2,950,196 Patented Aug. 23, 1960 methylbenzothiazole, S-methylbenzothiazole, 6-r'nethylbenzothiazole, S-bromobenzothiazole, 6-bromobenzothiazole, 4-phenylberrzothiazole, S-phenylbenzothiazole, 4- methoxybenzothiazole, S-methoxybenzothiazole, 6-methoxybenzothiazole, 6-iodobenzothiazole, 5,-iodobenzothiazole, 4-ethoxybenzothiazole, S-ethoxybenzothiazole, 5,6- dimethylbenzothiazole, S-hydroxybenzothiazole, 6-hydroxybenzothiazole, etc.), a heterocyclic nucleus of the naphthothiazole series (e.g., a-naphthothiazole, B-naphthothiazole, 7-methox*u-naphthothiazole, 8-methoxy-anaphthothiazole, 5-methoxy-5-naphthothiazole, S-ethoxyu-naphthotbiazole, etc.), a heterocyclic nucleus of the benzoselenazole series (e.g., benzoselenazole, S-chlorobenzoselenazole, -methoxybenzoselenazole, 5-methoXy benzoselenazole, etc.), a heterocyclic nucleus of the 'naphthoselenazole series (e.g., a-naphthoselenazole, pnaphthoselenazole, etc.), a heterocyclic nucleus of the benzoxazole series (e.g., benzoxazole, S-hydroxy-benzoxazole, 6-hydroxybenzoxazole, S-chlorobenzoxazole, 5- .rnethoxybenzoxazole, -methoxybenzoxazole, S-phenylbenzox-azole, S-bromobenzoxazole, etc.), a heterocyclic nucleus of the naphthoxazole series (e.g., u-naphthoxa zole, fi naphthoxazole, etc.), a heterocyclic nucleus of the 2-quinoline series (e.g., Z-quinoline, 6-methyl-2- quinoline, 7-methyl-2-quinoline, 8-methyl-2-quindline, 6-chloro-2-quinoline, 8-chloro-2-quinoline, 4-chloro-2- quinoline, S-ethoxy-Z-quinoline, 6-ethoxy-2-quinoline, 7- ethoxy-Z-quinoline, 6-hydroxy-2-quinoline, 7-hydroxy-2- quinoline, 6-methoxy-2-quinoline, etc.), a heterocyclic nucleus of the 4-quinoline series (e.g., 4-quinoline, 6- methoxy-4-quinoline, 7-methyl-4 -quinoline, 8-methy1-4- quinoline, etc.), a heterocyclic nucleus of the benzimidazole series (e.g., benzimidazole, S-chlorobenzimidazole, 5,6 7 dichlorobenziruidazole, 1,7 trimethylenebenzimidazole, etc.), and a heterocyclic nucleus of the 5,6-benzoquinoline series (e.g., 5,6-benzo-2-quinoline, etc.), and Z represents the non-metallic atoms necessary to complete a heterocyclic nucleus selected from the group consisting of those of the benzoxazole series (e.g., such as those defined by Z above), those of the naphthoXazole series (e.g., such as those defined by Z above), those of the benzoselenazole series (e.g., such as those defined by Z above), those of the naphthoselenazole series (e.g., such, as those defined by Z above), those ofthe benzothiazole series (e.g., such as those defined by Z above), and those of the naphthothiazole series (e.g., such as those defined by Z above).

The triazine compounds useful in practicing our invention comprise symmetrical triazine (i.e., 1,3,5-triazine) compounds, which can be simple triazine compounds or more complex polynuclear compounds. Such compounds comprise simple s-triazine compounds, such as those having an arylamino or substituted arylamino 'sub stituent, an alkylamino substituent (particularly those substituents having seven or more carbon atoms), a heterocyclyl substituent, etc., or more complex structures, such as the bistriazinylaminobibenzyl compounds, bistriazinylaminocarbazole compounds, etc. The supersensitizing efiect of these compounds appears to be a function of the s-triazine ring, as evidenced by the variety of compounds having this structure which have been found useful in our invention.

The bis-triazinylaminobibenzyl compounds useful in practicing our invention comprise those compounds represented by the following general formula:

(e.g., methoxyl, ethoxyl, etc.), a halogen atom (e.g.,

2,2-disulfonic acid (6)' 4,4-bis[4-phenoxy-6-(B-hydroxyethyl)amino s triazin-Z-ylamino] bibenZyl-2,2-dis ulfonic acid (7) 4,4-bis(4-anilin0-6-l1ydroXy-s-triazin-2 ylamino)- bibenzyl-2,2-disulfonic acid (8) 4,4'-bis[4-N-morpholinyl-6-(4-sulfoanilino) s triazin-Z-ylamino]bibenzyl-2,2'-disulfonic acid (9) 4,4'-bis[4-chloro-6-di(fi-hydroxyethyl)amino s triazin-2-ylamino]bibenzyl-2,2-disulfonic acid (10) 4,4'-bis[4-anilino-6-(fi-hydroxyethyl) amino s triazin-Z-ylamino]bibenzyl-2,2'-disulfonic acid 'The bis-tiiazinylaminocarbazole compounds useful in practicing our invention comprise those represented by the following general formula, although related compounds having a substituent on the nitrogen atom of the chlorine, bromine, etc.), a heterocyclic radical (e.g., carbazole nucleus can also be employed to advantage. morpholinyl, piperidyl, etc.), an alkylthio group (e.g.,

methylthio, ethylthio, etc.), an arylthio group (e.g., In H phenylthio, tolylt-hio etc.), a heterocyclylthio group 1 (e.g., benzothiazylthio, etc.), an amino group, an alkyl- 7 amino group (e.g., methylamino, ethylamino, propylv R H R amino, dimethylamino, diethylamino, dodecylamino, 6 WI f T 2 cyclohexylamino, fi-hydroxyethy'lamino, di-fl-hydroxy- N N N ethyl-amino, B-sulfoethylamino, etc.), an arylamino group y y (e.g., aniline, om-, and p-sulfoanilino, o-, m-, and p- R7 7 R3 chloroanilino, o-', m-, and p-a'nisylamino, 0-, m-, and ptoludino, 0-, mand -carbox anilino, h drox anilino, n I it a r V sulfonaphthylamino, 0 m-, Zind p-ami r ioanilino, p- W m R2 7 R r 1 F each have h values acetamidoanilino, etc.), a heterocyclylamino group (e.g., glyen Representative theqNnpounds repre, 2-benzothiazylamino, 2-pyridylamino, etc.), etc., and R sented by Formula 111 abOYe are those listed below. A1- and each represents a hydrogen atom or a waterthough the t frmu1a.s.are glven for h fi two solubilizing group, such as sulfo, oarboxyl, etc. (as Well PQ n the same numbering System was employed as alkali metal or amine salts of such groups Listed throughoutbelow are representative compounds selected from those represented by Formula II, although our invention is not 7 (n) limited in any sense to these particular compounds. a

While the structural formulas are included for only the N N first three compounds, it is to be understood that the f T H* rT same numbering system is employed throughout the N L L i specification. W V y p NH NH l N N V s 110( w-NHQCHrCHTQNH-F Torr N N sour 60311 H OH SOaH SIOQH 4,4'-b1s (4, 6-dihydroxy-s-triazin-Z-ylamino) bibenzyl-2,2- 2,8-bis [4- (4-sulf0ani1ino) -6-hydroxy-s-triazln-2-ylamino] V disulfonic acid carbazole v N N uo-omommkr TNHOHrCH NH f TNKJHZCHPOEDZ.

N N 0311 sou; Y N N erriam-0mg Nwmcm on 'gy-bis [4,6411(B-hydroxyethyl)amino-s-trlazin-2-ylamino]- bibeuzyl-2,2-disulfonic acid k a N (12) HzN-r m-NHQCHrCHQ-GNH-K NHa N N S0311 S OsxH N N 0 s N -NH s o r w NE NH: 4,4'-bis'(4,6-diamino-s-triazin-Z-ylamino)bibeuzy1-2,2'- I dlSlllfOIllC acid NH (3d) '4,4'-bis(4-chloro-6-trimethylolmethylamino s -triaziu-Z-ylamino)bibenzyl-2,2'-disulfonic acid a 4 4,4-bis[4-(4-sulfoanilino) 6 m hydroxyethynamino-s-triazin-Z-ylamino]bibenzyl-2,2-disu1fonic acid I I (5) 4,4'-bis(4,6-dianilino-s-t1ia2in-2 ylamino)bibenzyl- $03K 2,8-bis [4- (4-sulfoani1ino -6-morpholino-s-trizizih-Z-ylamlnol caruazole (13) '2,8-bis[4-(4-sulfoanilino) -6-piperidino s triazin- 2-ylamino] carbazole (14) .2,8-.bis [4-anilino-6- fi-hydroxyethyl) amino s triazin-Z-ylamino] carbazole (15) 2,8-bis [4-chloro-6-di(fi-hydroxyethynarnino s triazin-2-ylaminol carbazole More simple triazine compounds which can be employed in practicing our invention comprise those repre- 'According to our invention, we incorporate one or sented by the following general formula: more of the dicarbocyanine dyes represented by Formula N I above with one or more triazine compounds, such as Err YR: those represented by Formulas H, III or IV above. Our

i 5 invention is particularly directed to the ordinarily em- N ployed gelatino-silver-halide emulsions. However, our

supersensitizing combinations can be employed in silver a halide emulsions in which the carrier is other than gelah i R R d R h h h values given b tin, e.g., a resinous substance or cellulosic material which Representative compounds selected from those of Formu- 10 has 110 deteriorating efiect 011th? light-Sensitive materialsla IV comprise the following. While only the first four The dicarbmyanine y and 12111113 OOIIIPQImdS can be compounds are identified by structural formulas, the employed in various concentrations depending upon the same numbering system is employed throughout. effect? deS ired- (l6) SOBH Ordinarily, the optimum or near optimum concentration of the dicarbocyanine dyes which we employ in H0 practicing our invention is of the order of from 0.010 to f I 0.30 g. per mol. of silver halide in the emusion.

The triazine compounds which we employ in our invention can advantageously be employed at a concentra NHAJHZCHPOH tion of from about 0.03 to 10.0 g. per mol. of silver 2-(3-sulfoanilino)-6-hydroiry-? -(B-hydroxyethyDamino-s: halide m the emulslon' trlaztne In general, the ratio of concentration of dicarbocyanine dye to triazine compound can vary rather wide- (17) HZN 0 ly in our combinations, e.g., from 1=1 to 1=300 (by I weight) in many cases. N N The methods of incorporating sensitizing dyes in silver halide emulsions are well known to those skilled in the NHZ' art. The triazine compounds can be directly dispersed 2 4, diamin0 6-(2 fury1) s-tfiazine in the emulsions, or they can be dissolved in water (or (18) H N H Bier-NY Tut-QoH=0HoH=0H@NH( TN-om5 N N H s o H N N V S a a Nn-cmonron mnemomon 1,4-bls [4.- (4 anilino-S-B-hydroxyethylamlno-s-trlazin-Z- ylamino) -2sulfostyryl] benzene N N H0HzOHzCHN( TNHGGNH I NHCHzCH;-OH

N N l I N. N \l S0311 SOZH I \I HOH2CH2CNH NH-CH2CH2OH 4,4='-bis(4,6-di (fl hydroxyethylamino)-s-triazin-2-y1)benzidine- 2,2 -disulf0nic acid (20) 4,4-bis [4,6-di(,8-hydroxyethylamino)-s-triazin 2- an organic solvent, such as methanol, ethanol, etc., where ylamino] diphenylamine the water-solubility is not sufficiently great) and added (21) 2-chloro-4,6-di(fi-hydroxyethylamino)-s-t1iazine 50 in the form of their solutions. While the dicarbocyanine (22) 2-laurylamino-4,6-di(4-sulfoanilino) -s-triaz;ine dyes can be directly dispersed in the emulsions, it is con- (23) 2,4-diamino-6-(2-hydroxyphenyl) -s-triazine venient to add the same in the form of solutions in 21p (24) 2,4-diamino-6-methyl-s-triazine propriate solvents. Methanol, ethanol, pyridine, and the (25) 2,4-diamino-6-(3-hydroXy-2-naphthyl)-s-triazine like have proven satisfactory for many of the dyes of (26) 2,4-diarnino-6-(Z-hydroxystyryl) -s-triazine Formula I. Mixtures of solvents, e.g., pyridine diluted (27) 2,4-diamino-6-(2-hydroxy-3 -nitrophenyl) -s triwith methanol or acetone, can also be used. The diazine carbocyanine dyes and triazine compounds are dispersed (28) 2-amino-4-namyl-6-N-morpholinyl-s-triazine in the finished emulsions and should be uniformly dis- (29) 2-amino-4-(4-chloroanilino)-6-methy1-s-t1iazine tributed throughout the emulsions. The following pro- (30) 2-amino-4-N-morpholinyl-6-phenyl-s-triazine 60 cedure is satisfactory: Stock solutions of the dicarbo- (31) 2-(4-anisyl)-4,6-di(ethylamino)-s-triazine cyanine dyes and triazine compounds are prepared by (32) 2,4-diamino-6-decyl0Xy-s-triazine dissolving the same in appropriate solvents as described (33) 2,4-diamino-6-hendecyl-s-triazine above. Then, to the flowable gelatino-silver-halide emul- (33a) 2,4-dichloro-6-(2-pyridylamino)-s-triazine sion, the desired amounts of the stock solution of one of (34) 2-(4-chloroanilino)4-diethylaminoethylamino 6- 69 the dyes (or triazine compounds) are slowly added, While methyl-s-tn'azine stirring the emulsion. Stirring is continued until the dye (35) 2-amino-4-chloro-6-( l-piperidyl) -s-triazine is thoroughly incorporated in the emulsion. Then the de- (36) 2-amino-4-(2-pyridylamino) -s-triazine sired amount of the stock solution of the triazine com- (37) 2,4diamino-6-(5-pyrimidyl)-s-triazine pound (or dye, if triazine compound has been added (38) 2,4-diamino-6-(4-quinolyl)-s-triazine 70 first) is slowly added to the emulsion, while stirring. (39) 2,4-diamino-6-(2-thienyl)-s-triazine Stirring is continued until the second solution is (40) 2-amino-4-n-butylamino-6-(l -ethyl)amyl s trithoroughly incorporated. The supersensitized emulsion azine can then be coated out on a suitable support, such as (41) 2-(2-benzothiazylamino)-4,6-dichloro-s-triazine glass, cellulose derivative film, resin film, or paper, to a (42) 2-(2-benzothiazylamino)-4,6-dihydroxy-s-triazine 7 suitable thickness and allowed to dry. The details of following composition;

such coating methods are well known to those skilled in the art. Theforegoing procedures and proportions are to be regardedonly as illustrative. Clearly, our invention isdirected to any silver halide emulsion containing a combination of the aforesaid dicarbocyanine dyes and triazine compounds whereby a supersensitizing efiect is obtained. w

The following examples will serve to .illustrate'further the manner of practicing our invention. 1 In Table I below, to difierent portions of the same batch of photographic gelatino-silver-bromiodide emulsion were added (1) a dicarbocyanine dye, such as those represented by Formula I above, and (2) a combination of'the-dicarbocyanine dye' and a triazine compound (in neutral aqueous solution). Then the emulsions were held at-about 5052 'C. for a short time and coated on a support, chill set, and dried. 'After' exposure through a Wratten No. 2 5 filter, i.e., 'a filter whichtra'nsrnitssubstantially no light of wavelength shorter than about 5 80 run, in an- Eastman Type 113 sensitometer, the filmstrips were processed for 4 minutes in a developer having the N-methyl-p-aminophenol sulfate V 1 2.0 Hydroquinone 8.0 Sodium sulfite (desiccated) 90.0 Sodium carbonate (monohydrate) 52.5 Potassium bromide '5.0

Water to make '1 liter.

The speed (red), gamma and fog for each of the coatings was then measured. The results are recorded in Table I.

7 TABLE I cal .isensiti'zers; e.g., sulfur; 'sehsitizers '.(.e;g.,"allyl :thi'm carbamide, thiourea, allylisothiocyanate, cystine, etc), various gold compounds (e.g., potassium chloroaurate, auric trichloride, etc.) (see U.S. Patents 2,540,085; 2,597,856 and 2,597,915 various palladium compounds, such as palladium chloride (U.S. 2,540,086), potassium chloropalladate (U.S. 2,598,079), etc., or mixtures of such sensitizers; antifoggants,'such as ammonium chloroplatinate; (U.S.. 2,566,245.), ammonium chloroplatinite (U.S. 2,566,263), benzotriazole, nitrobenzimidazole, 5- nitroindazole, benzidine, mercaptans, etc. (see Mees-- The Theory ofthe Photographic Process, Macmillan Pub., page'460), or mixtures thereof; hardeners, suchas formaldehyde (U.S. 1,763,533), chrome alum (U.S. 1,763,533), glyoxal (U.S. 1,870,354), dibromacrolein (Br. 406,750), etc; color couplers, such as those described in U.S. Patent 2,423,730, Spence and Carroll U.S. Patent 2,640,776, etc.; or mixtures of such addenda. Dispersing agents for color couplers, such as those set forth in U.S. Patents 2,322,027 and 2,304,940, can also be employed in the above-described emulsions.

Such silver halide emulsions can also contain thiazoli dones orother ultravioletabsorhing compounds, such'as those described in the copending application Serial No. 419,239, filed March 29, 1954 in the name of G. W. Sawdey (now U.S. 'Patent 2,739,888, issued March 27, 1956). While certain emulsion addenda, such as certain ultraviolet compounds, and certain color-forming compounds cause de-sensitization or un-sensitizing effects, it has been found that the new combinations of our invention largely overcome such eifects; Typical colorforming compounds which can be so employed include those in U.S. Patent 2,322,027 and the following:

7 Red Light Exposure.

Example sensitizing Dye and Addenda (g./mol. AgX) Relative Gamma Fog Speed 1 {(11) 3,3-diethyloxathiadicarbocyahine iodide (.05)- 100 4.7 .06 (b) dye (a) (.050) plus compound 1 (4.0) 465 5.6 .09 2 (c) dye (a) (.050) plus compound 2 (4.0) 485 5.1 .09 3 {(d) dye (a) (.050) 100 4.5 .05 (e) dye (a) (.050) plus compound 2 (4.0). 535 4.5 .05 4 {(j) 3-ethyl-3-fi-hydroxyethyloxathiadicarbocyanine iodide (.050) 240 4.9 .07 (a) dye (I) (.050) plus compound 2 (4.0) 735 4.8 .05 5 {(h) 3,3 liethyl 5 phenyloxathiadicarbocyanine-p-toluenesulfonate 37 3. 0 08 (i) dye (h) (.050) plus compound 2 (4.0) 370 4. 7 .06 6 {(1') (Isma l-3'65 -hydroxyethyl-5-pheny1oxathiadicarbocyanine bro- 137. 5.3. .07 m1 e (k) dye (j) (.050) plus compound 2 (4.0); 640 4. 5 .06

COUPLER a In the above table, the coatings of Examples 1 and 2 were made from the same batch of emulsion and the coatings of'Examples 3, 4, 5 and 6 were made from the same batch of emulsion. No measurements of coatings containing only the triazine compound alone are given, since numerous coatings at the concentrations used in the table have shown that these triazine compounds alone have little or no measureable sensitizing efiect on the emulsions.

'Our invention is primarily directed to the ordinarily employed. gelatino-silver-halide developing-out emulsions, e.g., -gelatino-silver-chloride, -chlorobromide,- -chloro iodide, -chlorobromiodide, -bromide and -bromiodide developing-out emulsions. Emulsions which form the latent image mostly inside the silver halide grains, such as the emulsions set forth in U.S. Patent 2,456,956, dated December 21, 1948, can also be employed in practicing our invention.

The emulsions prepared in accordance with our invention can be coated in the usual manner on any suitable support, e.g., glass, cellulose nitrate film, cellulose acetate film, polyvinyl acetal'resin film, paper or metal.

Photographiosilverhalide emulsions, such as those listed above, containing the supersensitizing combinations .of our invention can. also contain such addenda. aschemil ('1) 1 ,hydroxy 2-[5-(2,4'-di-tert.a1nylphenoxy n butyll-naphthamide (U.S. 'Patent 2,474,293)

(2) 11' hydroxy 4 phenylazo 4' (p tert.-butylphenoxy)-2-naphthanilide (US. Patent 2,521,908) (3) 2 (2,4 di tert.amylphenoxyacetamino) 4,6-

dichloro-S-methyl phenol (Graham U.S. application Serial No. 285,544, now U.S. Patent 2,725,291)

(4) 2 (a-2,4-di-tert.amylphenoxy n butyrylamino)- 4,6-dichlo'ro-5-methyl phenol 1 (5) 6 {a -.{4 [a (2,4-di-tert.amylphenoxy)butyramido] phenoxy}acetamido} 2,4 dichloro 3 methyl phenol (6) 2 [3' (2'24" diamylphenoxy) -'acetarnido]-benzamido 4 chloro 5 methyl phenol (7) 1 (2,4',6 trichlorophenyl) 3 [3"-(2",',4 ditert.-amylphenoxyacetamido) benzamido] 5 pyrazolone (U.S. Patent 2,600,788) 7 (8) 1 (2,45,6, trichlorophenyl) 3 .[3"-(2'.",4"'?ditert. amylphenoxyacetamido) benzamido] 4 (pmethoxyphenylazo)15-pyrazolone (9) N (4 benzoylacetaminobenzenesulfonyl) N ('yphenylpropyD-p-toluidine (U.S. Patent 2,298,443 (10) d io methoxybenzoyl a chloro .4' -[a (2,4;- di. -..tert.- amylphenoxy) n butyramidol acetanilide a in The following table and examples will serve to illustrate the beneficial efiects of our new supersensitizing combinations when employed in a photographic emulsion containing a dispersion of a coupler or color-forming compound. In Table II these eifects are illustrated for the same batches of emulsions employed in arriving at the data in Table I. To a separate portion of each of the emulsions set forth under Table I above was added The coatings in the following examples were prepared and processed exactly as described for the coatings of Table I, except that exposure was made in an intensity scale sensitometer (using Wratten No. 25 filter). The emulsions were coated on a glass plate and chill set before exposure. The coatings of Examples 13, 14 and 15 Were made from the same batch of gelatino-silver-bromiodide emulsion, the coatings of Examples 16, 17, 18, 19, 20, 21 and 22 were made from the same batch of gelatinosilver-bromiodide emulsion, the coatings of Example 23 were made from the same batch of gelatino-silver-bromiodide emulsion, the coatings of Examples 24 and 25 were made from the same batch of gelatino-silver-bromiodide emulsion, and the coatings of Examples 26 and 27 were made from the same batch of gelatino-si lver-bromiodide emulsion.

TABLE III Red Light Exposure Example sensitizing Dye and Addenda (gJmol. AgX) Relative Gamma Fog Speed dye (a) (.050) 100 4.2 .06 dye (a) (.050) plus compound 18 (4.0) 380 5. 3 07 dye (a) (.050) plus compound 19 (4.0)-. 270 5. 3 .08 dye (a) (.050) plus compound 20 (4 0) 280 4. 6 .07 dye (a) (.050 100 4. 8 .06 dye (a) (.050) plus compound 21 230 4. 4 10 dye (a) (.050) plus compound 22 (4.0).. 370 4. 6 .06 dye (a) (.050) plus compound 23 (4.0) 245 4.4 .07 dye (a) (.050) plus compound 24 (4.0) 169 4. 6 10 dye (a) (.050) plus compound 25 (4.0) 185 4. 1 10 dye (a) (.050) plus compound 26 (4.0).. 670 4.1 .43 dye (a) (.050) plus compound 27 (4.0) 161 4. 5 12 dye (a) (.050) 100 4.8 .06 dye (a) (.050) plus compound 11 (4.0).. 465 4. 7 .06 dye (a) (.050) 100 4.5 .06 dye (a) (.050) plus compound 12 (4.0).. 210 4. 1 .06 dye (a) (.050) plus compound 13 (4.0).. 445 5.2 .07 dye (a) (.050) 100 3.9 .04 dye (a) (.050) plus compound 41 (4.0) 885 1. 8 .06 (e') dye (a) (.050) plus compound 42 (4.0 285 4. 5 .06 (e) dye (a) (.050) plus compound 3a (4.0).. 205 5.2 .06

a coupler dispersion containing coupler No. 5 of the above list. The emulsions were then held for the times indicated in the table below. After exposure and development of the coatings (exactly as in Table I), the relative red speed, gamma and fog for the coatings was measured. The results are given in Table 11 below. (The example numbers referred to in the table are those of Table I.)

TABLE II Example 28 Speed Gamma Fog D P1 HTolding Red Light Exposure control 100 4.1 .05- Example Emu151nf Relative Gamma control plus triazine (No. 16)- 535 5.3 .07

Speed g8 The data in the following table were obtained from s Example2 30 640 3.5 .09 coatings of an ordinary gelatino-silver-bromiodide emul- 9 89;: 28 2 $12 :93 sion in precisely the manner described for the coatings 10 {Example4 (1)---- e0 14 .60 .15 of Table I. These coatings were also processed in the Eggs? 83:: 2g 3g 3:? X5 same manner as those of Table I. The speed (red), 11 "{Example5 11)---- so 295 3.1 .13 gamma and fog for the exposed coatings are given in 12 52 2g g; i Table IV below. All coatings were made from the same batch of emulsion.

TABLE IV Red Light Exposure Example sensitizing Dye and Addenda (g./m0l. AgX) Speed Gamma Fog 29 {(f) 3,3-diethylthiadicarbocyanine iodide (.050). 5.4 .76 .06 (g') dye (f) .050) plus compound 1 30 (h) dye (f) (.050) plus compound 18 (1.0) 26.0 2.4 .06

(2") 3,3-d.iethylse1enadicarbocyanine bromide 21 5o 5.7 .96 .06 (j) dye (1") (.050) plus compound 1 (1.0)..-- 18.0 2.0 .06 32 (k) dye (i') (.050) plus compound 18 (1.0) 18. 5 2. 5 .06

11 .Thedyes'represented byFormulaI .ahove comprise a lwell known classof optical sensitizing dyes. While these 'dyes have been described in the prioratt, methods for making'them are also described in Carroll, Jones and Spence US. application Serial No. 540,052filed on even dateherewith;

. The triazine compounds employed in our invention, e;g., those of Formulas II, HI and IV above, have, in general, been described in the prior art. The bibenzyl compounds of Formula II and the carbazole compounds of Formula III, for example, can be prepared in exactly the same manner as the stilbene. compounds of Serial No. 540,052 'by employing the corresponding diamino bibenzyl and diaminocarbazole compounds. Thus these corresponding diamino compounds can be condensed with cyanuric chloride (step 1 of Serial No. 540,052), followed by condensation with ammonia or an amine (step 2), and/or hydrolysis (step 3) or-condensation with further ammonia or amine. See also British Patent 616,523, accepted January 24, 1949 for this method. The preparation of a number of the compounds of Formulas II and III can be summarized as follows:

We have also found that the compounds of the type represented .by Formulas II, III and IV above can advantageously be employed in photographic silverhalide emulsions, and particularly photographic silver bromiodide emulsions (negative speed), containing color-forming or coupling compounds of the type described above to prevent or diminish the formation of spontaneous fog which develops upon exposure of the emulsionsto high temperatures and humidity. Also, we have found that the s-triazine compounds of our'invention have the valuaole property of inhibiting the formation of stain which frequently remains after processing of photographic emulsions containing color-forming compounds. The antifoggant' and/or anti-stain action of these compounds appears to be unrelated to the supersensi-tizing'efiect shown in the above examples. ,That is, this anti-foggant or anti-stain action "appears to'take place regardless of the presence of sensitizing dyes in the emulsions containing the color-forming compounds of the type mentioned above.

The anti-foggant and/ or anti-stain action of the s-triazine compounds of our invention appears to be particu- Usedin Step 2 Compound Used in Step 1 Step 3 methane (2 mols.).

,rin

4,4-diaminodiphenylarnine (trishydroxymethyD-aminoflaminoethanol (2 mols.) hydrolysis B-aminoethanol (2 mols.) sodigm sulfam'late (2 mols.) o

B-aminoethanol (2 mols.)

Omitte d.

B-aminoethanol (2 mols.). hydrolysis. fi-aminoethanol (2 mols.). hydrolysis.

morpholine (2 mols.). piperidine (2 mols.) fl amtnoethanol (2 mols.)

jThe diamine compound required to prepare compound 18 was prepared as follows: a e

p-Nitrotoluene was treated With chlorosulphonic acid to form p-nitrotoluene-Z-sulphonylchloride. This compound was converted into its phenylester with sodium phenoxide. This product was condensed with terephthalaldehyde to' yield 4:4"-dinitro 1:4-distyrylbenzene- 2':2"'-disulphonic acid phenylester; The terephthalaldehydevwas prepared by the tetrabromination of p-xylol and subsequent hydrolysis of the bromination compound with sulphuric acid.

' The 4 :'4"-dinitro-1 :4-distyrylbenzene-2' 2-disulfonic acid phenyl ester was then reduced to the corresponding 4:4"-diamino compound with Raney nickel and the ester hydrolyzed to the free sulfonic acid with aqueous alkali. (British 668,200.)

" The triazine compounds represented by Formula IV above comprise many known compounds. While methods for making these compounds are also well known, :the following example will serve to illustrate the preparation of one of these compounds.

Example 33 .2-laurylamin0-4,6-di (4-sul foani lino) -striazine One hundred and twenty-four parts of 6-chloro2,4-di- (sodium-p-sulfophenylamino)-3-triazine (prepared as in step 2, using sulfanilic acid and cyanuric chloride) and 92 parts of laurylamine were stirred in dimethylformamide at 145-150 C. for 5-6 hours. The white solid which was collected from the cooled reaction mixture was suspended in Water containing 10 parts of sodium hydroxide and extracted with ethylether. The water layer was concentrated to dryness, and the remaining solid treated with ethyl ether several'times. Eighty-eight parts of a white solid was obtained. The free acid was obtained upon acidification.

Other triazine compounds of Formula IV can be simi larly prepared. For example, compound 41 was obtained simply by condensing cyanuric chloride with 2- aminobenzothiazole. Hydrolysis of compound 41 (step 7 3) gave compound 42.

larly outstanding in the presence of color-forming compounds for the magenta or cyan images, i.e. in the presence of magenta or cyan couplers (e.g. such as the magenta and cyan couplers. described in US. Patent 2,640,776 mentioned above). The anti-foggant and antistain action of the s-triazine compounds of our invention is particularly apparent at concentrations of 1 gram of compound per mole of. silver halide, or amounts in excess of 1 gram (e.g., from about 1 to 1.0grams per mole of silver halide). It has also been found that the s-triazine compounds of our invention are particularly useful in combination with color couplers of the water-soluble type (such as the couplers described in U.S; application Ser. No. 470,499, filed November 22, 1954) now US. Patent 2,808,329, issued October 1, 1957. Such couplers when used in the absence of the s-triazine compounds cause sufiiciently high fog to make their use difficult in photographic emulsions. However, when using such couplers in the presence of our s-triazine compounds, the fog is reduced to a considerable degree so that such couplers. can be employed from a practical standpoint.

The following example will serve to illustrate the anti- .foggant action of our s-tn'azine compounds when em.-

ployed in a photographic silver halide emulsion containmg a color-forming compound. e

Example 34 A red sensitive chloro bromide emulsion containing a color coupler, such as coupler No. 5 above, was divided into two batches and these batches coated on cellulose acetate supports and dried. One coating was exposed in an intensity scale sensitometer through a Wratten No. 25 filter, while the second coating was incubated at F. (50% relative humidity) for seven days before exposure. The exposed coatings were then processed as described in Example 46 of our copending application Ser. No. 540,052, filed on even date herewith. The fog measurements for the coating which contained no antifoggant is compared in the following table with an exact coating which contained 2,4-diamino-6n-heptadecyl-s-trii3 azine (in the amount shown in the table). The results follow.

A=2,4diamix6-n-heptadecyl-s-triaziue.

As shown in the above examples, the compounds of Formulas II, III and IV above are generally employed in neutral aqueous solution, when such compounds contain 'a free sulfonic acid group. That is, the free acids are at least partially neutralized with sodium hydroxide, potassium hydroxide, sodium carbonate, ammonia, triethylamine, etc. before use in the emulsions. The corresponding sulfonic acid salts result. It is thus possible to adjust the pH of these aqueous solutions so that they are about the same as the pH of the emulsions.

The accompanying drawing illustrates the supersensitizing effect obtained with three of our new combinations in gelatino-silver-bromiodide emulsions. Each figure of the drawing is a diagrammatic reproduction of one or two (Fig. 1) spectrograms. The sensitivity of the emulsion containing only the dicarbocyanine dye represented by Formula I is represented by the broken line in Fig. 1, while the sensitivity of the same emulsion containing both a dicarbocyanine dye of Formula I and a triazine compound of Formulas III or IV is represented by the solid curve. The sensitizing dye used in Fig. l was also employed in the coatings of Figs. 2 and 3, hence curve A of Fig. 1 is not reproduced in Figs. 2 and 3 since it would merely be identical thereto.

In Fig. 1, curve A represents the sensitivity of an ordinary gelatino-silver-bromiodide emulsion containing 3,3- diethyloxathiadicarbocyanine iodide, while curve B represents the sensitivity of the same emulsion sensitized with 3,3-diethyloxathiadicarbocyanine iodide and 2,8-bis[4- (4 sulfoanilino) 6 hydroxy s triazine 2 ylamino] carbazole. Sensitometric measurements for coatings prepared in substantially the same manner are given in EX- ample 23 above.

In Fig. 2, curve Crepresents the sensitivity of an ordinary gelatino-silver-bromiodide emulsion sensitized with 3,3'-diethyloxathiadicarbocyanine iodide and 2,4-diamino- 6-(2-hydroxystyryl)-s-triazine. Sensitometric measurements for coatings prepared in substantially the same manner are given in Example 21 above.

In Fig. 3, curve D represents the sensitivity of an ordinary gelatino-silver-bromiodide emulsion sensitized with 3,3'-diethyloxathiadicarbocyanine iodide and 6-hydroxy- 4 B hydroXyethyl-amino 2 (3 sulfoanilino) striazine. Sensitometric measurements for coatings prepared in substantially the same manner are given in Example 28 above.

What We claim as our invention and desire secured by Letters Patent of the United States is:

l. A photographic silver halide emulsion sensitized with a supersensitizing combination of at least one dicarbocyanine dye selected from the class represented by the following general formula:

those of the naphthoxazole series, those of the 1261126 selenazole series, and those of the naphthoselenazole series, and Z represents the non-metallic atoms necessary to complete a heterocyclic nucleus selected from the group consisting of those of the benzothiazole series, those of the naphthothiazole series, those of the benzoxazole series, those of the naphthoxazole series, those of the benzoselenazole series, those of the naphthoselenazole series, those of the 2-quinoline series, those of the 4- quinoline series, those of the benzimidazole series, and those of the 5,6-benzoquinoline series, and at least one compound containing at least one s-triazine ring.

2. A photographic silver halide emulsion sensitized with a supersensitizing combination .of at least one dicarbocyanine dye selected from the class represented by the following general formula:

wherein R and R each represents an alkyl group containing from 1 to 4 carbon atoms, 1 represents a positive integer of from 1 to 2, X represents an acid radical, Z represents the non-metallic atoms necessary to complete a heterocyclic nucleus selected from the group consisting of those of the benzothiazole series, those of the naphthothiazole series, those of the benzoxazole series, those of the naphthoxa'zole series, those of the benzoselenazole series, and those of the naphthoselenazole se ries, and Z represents the non-metallic atoms necessary to complete a heterocyclic nucleus selected from the group consisting of those of the benzothiazole series, those of the naphthothiazole series, those of the benzoxazole series, those of the naphthoxazole series, those of the benzoselenazole series, those of the naphthoselenazole series, those of the 2'-quinoline series, those of the 4-quinoline series, those of the benzimidazole series, and those of the 5,6-benzoquinoline series, and at least one triazine compound selected from the class represented by the following general formula:

wherein R and R each represents a lower alkyl group containing from 1 to 2 carbon atoms, n represents a positive integer of from 1 to 2, X represents an acid radical, Z represents the non-metallic atoms necessary to complete a heterocyclic nucleus selected from the group consisting of those of the benzothiazole series, those of the naphthothiazole series, those of the benzoxazole series, those of the naphthoxazole series, those of the henzoselenazole series, and those of the naphthoselenazole series, and Z represents the non-metallic atoms neces sary to complete a heterocyclic nucleus selected from the group consisting of those of the benzothiazole series, those of the naphthothiazole series, those of the benzoxazole series, those of the naphthoxazole series, those of the benzoselenazole series, those of the naphthoselenazole series, those of the Z-quinoline series, those of the 4-quinoline series, those of the benzimidazole series, and those of the 5,6-benzoquinoline series, and at least one triazine compound selected from the class represented by the following general formula:

SQsH SOaH wherein R and R each represents an alkyl group containing from 1 to 4 carbon atoms, n represents a positive integer of from 1 to 2, 'X represents an acid radical, Z represents the non-metallic atoms necessary to complete a heterocyclic nucleus selectedirom the group consisting of those of the benzothiazole series, those of the naphthothiazole series, those of the benzoxazole series, those of thetnaphthoxazole series, those of the benzoselenazole series, and those of the naphthoselenazole series, and Z represents the non-metallic atoms necessary to complete a heterocyclic nucleus selected from the group consisting of those of the benzothiazole series, those of the naphthothiazole series, those of the benzoxazole series, those of the naphthoxazole series, those of the benzoselenazole series, those of the naphthoselenazole series, those of the 2-quinoline series, those of the 4-quinoline series, those of the benzimidazole series, and those of the 5,6-benzoquinoline series, and at least one triazine compound selected from the class represented by the following general formula:

F TF

wherein R and R each represents an alkyl group containing from 1 to 2 carbon atoms, n represents a'positive integer of from 1 to 2, X represents an acid radical,

'Z represents the non metallic atoms necessary to complete a heterocyclic nucleus selected from the group consisting of those of the benzothiazole series, those of the naphthothiazole series, those of the benzoxazole sen'es, those of the naphthoxazole series, those of the benzoselenazole series, and those of the naphthoselenazole series, and Zyrepresentsth'e non-metallic atoms necessary to complete a heterocyclic. nucleus selected from the a 16 group consisting of those of the benzothiazole series, those of the 'naphthothiazole series, those of the benzoxazole series, those of the naphthoxazole series, those of the benzoselenazole series, those of the naphthoselenazole series, those of the 2-quinoline series, those of the 4-quinoline series, those of the benzirnidazole series,

and those of the 5,6-benzoquinoline series, and at least one triazine compound selected from the class represented by the following generalformula: t t

D-NH NH-Dl wherein D and D each represents a s-triazin-Z-yl nucleus.

6. A photographic silver halide emulsion sensitized with a supersensitizing combination of at least one dicarbocyanine dye selected from the class represented by the following general formula:

wherein R and R each represents an alkyl group containing from 1 to 4 carbon atoms, n represents a positive integer offrom 1 to 2, X represents an acid radical, Z represents the non-metallic atoms necessary to complete a heterocyclic nucleus selected from the group consisting of those of the benzothiazole series, those of the naphthothiazole series, those of the 'benzoxazole series, those of the naphthoxazole series, those of the benzoselenazole series, and those of the naphthoselenazole series, and Z represents the non-metallic atoms necessary to complete a heterocyclic nucleus selected from the a group consisting of those of the benzothiazole series, those of the naphthothiazole series, those of the benzoxazole series, those of the naphthoxazole series, those of the benzoselenazole series, those of the naphthoselenazole series, those of the Z-quinoline series, thoseof the 4- quinoline series, those of the benzimidazole series, and those of the 5,6-benzoquinoline series, and at least one triazine compound selected from the class represented by the following general formula:

wherein R R and R each represents a member selected from the group consisting of a hydrogen atom, a hydroxyl group, an aryloxyl group, an alkoxyl group, a halogen atom, a heterocyclic radical, an alkylthio group, an arylthio group, and an amino group.

7.'A photographic gelatino-silver-bromiodide emulsion sensitized with a superscnsitizing combination of at least one dicarbocyanine dye selected from the class represented by the following general formula:

needles consisting of those of the benzothiazole'series, those of the naphthothiazole series, those of the benzoXazole se ries, those of the naphthoxazole series, those of the benzoselenazole series, those of the naphthoselenazole series, those of the 2-quinoline series, those of the 4-quinoline series, those of the benzimidazole series, and those of the 5,6-benzoquinoline series, and at least one triazine compound selected from the class represented by the following general formula:

wherein R R and R each represents a member selected from the group consisting of a hydrogen atom, a hydroxyl group, an aryloxyl group, an alkoxyl group, a halogen atom, a heterocyclic radical, an alkylthio group, an arylthio group and an amino group.

8. A photographic gelatino-silver-halide developing-out emulsion sensitized with a supersensitizing combination or" a dicarbocyanine dye selected from the class represented by the following general formula:

h nt

wherein R and R each represents an alkyl group containing from 1 to 2 carbon atoms, X represents an acid radical, Z represents the non-metallic atoms necessary to complete a heterocyclic nucleus of the benzothiazole series and Z represents the non-metallic atoms necessary to complete a heterocyclic nucleus of the benzoxazole series, and at least one triazine compound selected from the class represented by the following general formula:

D-NHGCHz-CHQNH-Dr SOsH SOsH

wherein D and D each represents a s-triazin-Z-yl nucleus.

9. A photographic gelatino-silver-halide developing-out emulsion sensitized with a supersensitizing combination of 3,3-diethyloxathiadicarbocyanine iodide and at least one bis(s-triafin-Z-ylamino)bibenzyl compound selected from the class represented by the following general formula:

SOsH S Oafi wherein D and 1); each represents a s-triazin-2-yl nucleus.

10. A photographic gelatino-silver-halide developingout emulsion sensitized with a supersensitizing combination of 3,3'-diethyloxathiadicarbocyanine iodide and 4,4- bisl (2,4-di--hydroxyethylamino) -s-triazin-2- ylamino b ibenzyl-2,2-disulfonic acid.

11. A photographic gelatino-silver-halide developingout emulsion sensitized with a supersensitizing combination of a dicarbocyanine dye selected from the class represented by the following general formula:

wherein R and R each represents an alkyl group containing from 1 to 2 carbon atoms, X represents an acid radical, Z represents the non-metallic atoms necessary to complete a heterocyclic nucleus of the benzothiazole series and Z represents the non-metallic atoms necessary to complete a heterocyclic nucleus of the benzoxazole wherein R and R each represents an alkyl group containing from 1 to 2 carbon atoms, X represents an acid radical, Z represents the non-metallic atoms necessary to complete a heterocyclic nucleus of the benzothiazole series and Z represents the non-metallic atoms necessary to complete a heterocyclic nucleus of the benzoxazole series, and at least one triazine compound selected from the class represented by the following general formula:

wherein R R and R each represents a member selected from the group consisting of a hydrogen atom, a hydroxyl group, an aryloxyl group, an alkoxyl group, a halogen atom, a heterocyclic radical, an alkylthio group, an arylthio group, and an amino group.

14. A photographic gelatino-silver-halide developingout emulsion sensitized with a supersensitizing combination of 3,3'-diethyloxathiadicarbocyanine iodide and 2- 2-benzothiazylamino) -4,6-dichloro-s-triazine.

15. A photographic gelatino-siiver-halide developingout emulsion sensitized with a supersensitizing combination of a dicarbocyanine dye selected from the class represented by the following general formula:

wherein R and R each represents an alkyl group containing from 1 to 2 carbon atoms, X represents an acid radical, Z represents the non-metallic atoms necessary to complete a heterocyclic nucleus of the benzothiazole series and Z represents the non-metallic atoms necessary to complete a heterocyclic nucleus of the benzothiazole series, and at least one triazine compound selected from the class represented by the following general formula:

@cm-onQ-nn-m 50311 SOaH wherein D and D each represents a s-triazin-Z-yl nucleus.

16. A photographic gelatino-silver-halide developingout emulsion sensitized with a supersensitizing combination of 3,3'-diethylthiadicarbocyanine iodide and 4,4- bis(4,6 dihydroXy-s-trazin 2 ylamino)dibenzyl 2,2- disulfonic acid.

17. A photographic gelatino-silver-halide developingout emulsion sensitized with a supersensitizing combinawherein R and R each represents an alkyl group containing from 1 to 2 carbon atoms, X represents an acid radical, Z and Z each represents the non-metallic atoms necessary to complete a heterocyclict nucleus of the 'benzoselenazole series, and at least one triazine compound selected from the class represented by the following general formula V RFK TRQ V i N V N Ra wherein R R and R each represents a member selected from the group consisting of a hydrogen atom, a hydroxyl group, an aryloxyl group, an alkoxyl group, a halogen atom, a heterocyclic radical, an alkylthio group, an arylthio group, and an amino group.

18. A photographic gelatino-silver-halide developingout'emulsion sensitized with a supersensitizing combination of 3,3'-diethylselenadicarbocyanine. bromide and 1,4 -'bis [4-(4-anilino-6-B-hydroxyethylamino s triazin: 2-ylamino) -2-sulfostyryl] benzene.

19. A photographic silver halide emulsion capable of producing a dye image comprising a photographic silver halide emulsion containing (1) a dispersion of a phenol color-forming compound capable of coupling with the oxidation products of a primary aromatic amine developing agent to produce a cyan image, (2) a dicaroocyanine dye selected from the class represented by the a heterocyclic nucleus selected, from the group consisting of those of the benzothiazole series, those of the naphthothiazole series, those of the benzoxazole series, those of the naphthoxazole series, those of the benzoselenazole series, and those of the naphthoselenazole series, and Z represents the non-metallic atoms necessary to complete a heterocyclic nucleus selected from the group consisting of those of the benzothiazole series, those of the naphthothiazole series, those of the benzoxazole series, those of the naphthoxazole series, those of the benzoselenazole series, those of the naphthoselenazole series, those of the 2-quinoline series, those of the 4-quinoline series, those "20 of the benzimidazole series, and 'those of the 5,6-benzoquinoline series, and (3) a compound containing at least one s-triazine ring. V x

20. A photographic silver halide emulsion capable of producing a dye image, comprising a photographic silver halide emulsion containing (1)' a dispersion of a colorforming compound selected from theclass consisting of a phenolcompound and a pyrazolone compound, capable of reacting with the oxidation products of a primary aromatic amine developing agent to form a cyan dye image and a magenta dye image, respectively, and (2) a s-triazine compound selected from the class consisting of those represented by the following two general formulas:

RPKN CH OH NH m-R2 and V V wherein R R R and R each represents a member selected from the group consisting of a hydrogen atom, a hydroxyl group, an aryloxyl group, an alkoxyl group, a halogen atom, a heterocyclic radical, an alkylthio group, an arylthio group, and an amino group, and R and R each represents a member selected from the group consisting of a hydrogen atom and a sulfo group, said s-triazine compound being incapable of reacting with the oxidation products of a primary aromatic amine developing agent to form a dye image.

References Cited in the file of this patent I UIIITED STATES PATENTS 2,271,623 Carroll ....1 Feb. 3, 1942 2,397,867 Jennings Apr. 2, 1946 2,418,747 Bavley Apr. 8, 1947 2,422,080 Collins et al June 10, 1947 2,476,536 Dersch July 19, 1949 2,701,198 Carroll Feb. 1, 1955 2,718,466 Wolfson Sept. 20, 1955 FOREIGN PATENTS 675,656 Great Britain July 16, 1952 832,391 Germany Feb. 25, 1952 OTHER REFERENCES Mees: The Theory of the Photographic Process, MacMillan Co., N.Y., 1954, page 365. 

20. A PHOTOGRAPHIC SILVER EMULSION CAPABLE OF PRODUCING A DYE IMAGE, COMPRISING A PHOTOGRAPHIC SILVER HALIDE EMULSION CONTAINING (1) A DISPERSION OF A COLORFORMING COMPOUND SELECTED FROM THE CLASS CONSISTING OF A PHENOL COMPOUND AND A PTRAZOLONE COMPOUND, CAPABLE OF REACTING WITH THE OXIDATION PRODUCTS OF A PRIMARY AROMATIC AMINE DEVELOPING AGENT TO FORM A CYAN DYE IMAGE AND A MAGENTA DYE IMAGE, RESPECTIVELY, AND (2) A S-TRIAZINE COMPOUND SELECTED FROM THE CLASS CONSISTING OF THOSE REPRESENTED BY THE FOLLOWING TWO GENERAL FORMULAS: 